Handheld Electronic Device Comprising A Keypad Having Multiple Character Sets Assigned Thereto, With The Character Sets Being Individually Illuminable

Abstract

An improved handheld electronic device has a keypad that includes a plurality of different character sets selectively illuminable thereon. Different types of light and different mechanisms for delivering light provide the selective illumination of a particular character set. When a particular character set is illuminated, a corresponding character lookup table is active on the handheld electronic device whereby the processor determines the particular character or characters that were intended in an actuation of a key of the keypad.

1 . A handheld electronic device comprising:
 a processor apparatus comprising a processor and a memory;   an input apparatus structured to provide input to the processor apparatus and comprising a keypad apparatus;   an output apparatus structured to receive output signals from the processor apparatus;   the keypad apparatus comprising:
 a plurality of keys, at least some of the keys each comprising an illuminable first indicator which in an illuminated condition is indicative of a first character assigned to the key being active and an illuminable second indicator which in an illuminated condition is indicative of a second character assigned to the key being active; 
 a first illumination source structured to illuminate at least some of the first indicators; and 
 a second illumination source structured to illuminate at least some of the second indicators. 
   
   
   
       2 . The handheld electronic device of  claim 1  wherein at least one of the first illumination source and the second illumination source is a source of electromagnetic energy outside a spectrum visible to a user. 
   
   
       3 . The handheld electronic device of  claim 2  wherein the other of the first illumination source and the second illumination source is a source of electromagnetic energy within the spectrum visible to a user. 
   
   
       4 . The handheld electronic device of  claim 2  wherein the keypad apparatus further comprises a light pipe structured to transmit electromagnetic energy between the first and second illumination sources and the first and second indicators. 
   
   
       5 . The handheld electronic device of  claim 2  wherein an indicator that is illuminable by the at least one of the first illumination source and the second illumination source is substantially invisible in a non-illuminated condition. 
   
   
       6 . The handheld electronic device of  claim 1  wherein the keypad apparatus further comprises a first light pipe structured to transmit electromagnetic energy between the first illumination source and at least some of the first indicators, and wherein the keypad apparatus further comprises a second light pipe structured to transmit electromagnetic energy between the second illumination source and at least some of the second indicators. 
   
   
       7 . The handheld electronic device of  claim 6  wherein the first and second illumination sources each generate light in the visible spectrum. 
   
   
       8 . The handheld electronic device of  claim 1  wherein at most one of the first and second illumination sources is energized at any given time. 
   
   
       9 . A method of selecting an active alphabet for a text input on a handheld electronic device having available thereon a default alphabet and an alternate alphabet, the handheld electronic device comprising an input apparatus, the method comprising:
 determining that the text input is one of:
 a communication to a recipient to whom a previous communication was made employing the alternate alphabet, and 
 a reply to an existing communication that comprises a preexisting quantity of text at least a portion of which is in the alternate alphabet; 
   responsive to the determining, selecting the alternate alphabet as the active alphabet; and   illuminating on the input apparatus at least a portion of the alternate alphabet.   
   
   
       10 . The method of  claim 9 , further comprising energizing an illumination source and, responsive thereto, performing the illuminating. 
   
   
       11 . The method of  claim 10 , further comprising energizing as the illumination source an illumination source that generates electromagnetic energy outside a spectrum visible by a user, and illuminating as the at least portion of the alternate alphabet an indicator that is substantially invisible in a non-illuminated condition. 
   
   
       12 . The method of  claim 9 , further comprising de-energizing another illumination source and ceasing the illuminating on the input apparatus at least a portion of the default alphabet.